Search results
Results from the WOW.Com Content Network
The minimum distance between Earth and Mars has been declining over the years, and in 2003 the minimum distance was 55.76 million km, nearer than any such encounter in almost 60,000 years (57,617 BC). The record minimum distance between Earth and Mars in 2729 will stand at 55.65 million km.
Mars's average distance from the Sun is roughly 230 million km (143 million mi), and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. [185] A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. [2]
Average distance from the Sun — Earth: 1.00 — Average distance of Earth's orbit from the Sun (sunlight travels for 8 minutes and 19 seconds before reaching Earth) — Mars: 1.52 — Average distance from the Sun — Jupiter: 5.2 — Average distance from the Sun — Light-hour: 7.2 — Distance light travels in one hour — Saturn: 9.5 ...
Careful observations of the 1769 transit of Venus allowed astronomers to calculate the average Earth–Sun distance as 93,726,900 miles (150,838,800 km), only 0.8% greater than the modern value. [291] Uranus, having occasionally been observed since 1690 and possibly from antiquity, was recognized to be a planet orbiting beyond Saturn by 1783. [292]
Deimos (/ ˈ d aɪ m ə s /; systematic designation: Mars II) [11] is the smaller and outer of the two natural satellites of Mars, the other being Phobos. Deimos has a mean radius of 6.2 km (3.9 mi) and takes 30.3 hours to orbit Mars. [5] Deimos is 23,460 km (14,580 mi) from Mars, much farther than Mars's other moon, Phobos. [12]
The first two objects that were detected and had their Earth-MOID calculated before Earth impact were the small asteroids 2008 TC 3 and 2014 AA. 2014 AA is listed with a MOID of 0.00000045 AU (67 km; 42 mi), [5] and is the second smallest MOID calculated for an Apollo asteroid after 2020 QY 2 with an Earth-MOID of 0.00000039 AU (58 km; 36 mi). [6]
On 21 March 1963, when the spacecraft was at a distance of 106,760,000 km from Earth, on its way to Mars, communications ceased due to failure of its antenna orientation system. [44] [45] In 1964, both Soviet probe launches, of Zond 1964A on June 4, and Zond 2 on November 30, (part of the Zond program), resulted in failures. Zond 1964A had a ...
In 1672 Jean Richer and Giovanni Domenico Cassini measure the astronomical unit (AU), the mean distance Earth-Sun, to be about 138,370,000 km, [83] (later refined by others up to the current value of 149,597,870 km). This gave for first time ever a well estimated size of the then known Solar System (that is, up to Saturn), following the scale ...